Removing and Installing/Replacing Inlet and Exhaust Adjustment Units
11 36 046 Removing and installing/replacing inlet and exhaust adjustment units (N12)Special tools required:
Important!
Always release both central bolts to adjust the timing.
The timing is not determined at firing TDC of cylinder no. 1.
Modified procedure for timing adjustment.
All pistons are in the 90° position.
Check locking of adjustment units.
Necessary preliminary tasks:
^ Remove cylinder head cover.
^ Check timing.
Rotate crankshaft at central bolt.
11 9 590 Slide in special tool in direction of arrow and block crankshaft.
Release screws (1).
Remove slide rail (2).
Important!
Risk of damage!
To open central bolt, mount special tool on camshaft. 11 9 540
If the setting gauges cannot be positioned, grip the camshaft with an open-end wrench to release the central bolt.
Refer to Adjusting timing.
Release chain tensioner (1) (have a cleaning cloth ready).
Tightening torque: 11 31 4AZ.
Release bearing pin (1) on guide rail.
Tightening torque: 11 11 7AZ.
Installation:
Replace sealing ring.
Release central bolts of inlet adjustment unit (1) and exhaust adjustment unit (2).
Detach inlet adjustment unit from inlet camshaft.
Detach exhaust adjustment unit from exhaust camshaft.
Important!
^ Danger of mixing up adjustment units.
^ Mixing up the adjustment units will result in engine damage.
The inlet and exhaust adjustment units are different.
VANOS is marked with IN for the inlet camshaft.
VANOS is marked with EX for the exhaust camshaft.
Place adjustment units of exhaust camshaft marked EX on timing chain.
Position adjustment unit on exhaust camshaft and secure with central bolt (3).
The installation position of the adjustment units can be freely selected.
Place adjustment units of inlet camshaft marked IN on timing chain.
Position adjustment unit on inlet camshaft and secure with central bolt (1).
The installation position of the adjustment units can be freely selected.
Install slide rail (2).
Insert bolts (1).
11 9 340 Screw special tool into cylinder head.
Pretension timing chain with special tool to 00 9 2500.6 Nm.
Secure central bolt with special tool 1 00 9 120.
Tightening torque: 11 36 1AZ.
Secure central bolt with special tool 1 00 9 120.
Tightening torque: 11 36 1AZ.
Fit chain tensioner.
Check timing.
Assemble engine.
N12:
